The present invention relates to a process for producing propylene oxide by carrying out an epoxidation reaction of propylene using hydrogen peroxide. More specifically, the invention relates to a process for efficiently producing propylene oxide by performing the reaction using a specific crystalline titanosilicate catalyst having an MWW structure in the presence of an organic solvent.
As the process for producing propylene oxide by carrying out an epoxidation reaction of propylene using hydrogen peroxide, a method of using a TS-1 catalyst (e.g., Japanese Published Examined Application No. 4-5028) is known. The TS-1 catalyst is a crystalline titanosilicate catalyst having MFI structure in accordance with the framework type code of International Zeolite Association (IZA). In addition, when the TS-1 catalyst is used, a methanol solvent is known to be an appropriate solvent (e.g., Journal of Catalysis 129:159 (1991)).
Also, as a process for producing propylene oxide by carrying out an epoxidation reaction of propylene with hydrogen peroxide using MWW structure-having crystalline titanosilicate (hereinafter referred to as Ti-MWW) catalyst, there has been a known method that uses a Ti-MWW catalyst, into which titanium (hereinafter referred to as Ti) has been incorporated after crystallization (e.g., U.S. Pat. No. 6,114,551).
Moreover, as a process for producing propylene oxide by carrying out an epoxidation reaction of propylene with hydrogen peroxide, as a medium, using a Ti-MWW catalyst, into which Ti has been incorporated during crystallization, there has been a known method that produces propylene oxide in a water solvent, that is, in an aqueous hydrogen peroxide solution (Heisei 12 nendo Jisedai Kagaku Process Gijutu Kaihatu Non-halogen Kagaku Process Gijutu Kaihatu Seika Houkokusho (Report of R&D projects for “Next-generation Chemical Process Technology/Non-halogen Chemical Process Technology” FY2000 Annual Report) 261–268, (FY2001)).
However, in the conventionally known production methods, sufficient catalytic activities have not been attained.